Improvement in receiving-magnets for telegraphs



.lul jl C R-K--I Telegraphic-Relay Instrument.

' 616.46639.' Patented March 7, 1666.

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UNITED STATES PATENT OFFICE.

JAMES J. OLARK, OF NEW YORK, N. Y.

Specification forming part of Letters Patent No. 46,639, dated March 7,1865.

To all whom it may concer/n:

Be it known that I, JAMES J. CLARK, of the city of New York, State ofNew York, have invented a new and useful Improvement inTelegraphlnstruments, and I do hereby declare that the following is afull and exact description thereof, reference being had to theaccompanying` drawings, and to the letters of reference marked thereon.

Figure 1 is a side View, and Fig. 2 a top view.

The nature of my inventionv consists of an appliance by which a loudsound is produced by a very slight motion of the lever of the relay orreceiving magnet. v

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction andoperation.

I take a receivingmagnet of the ordinary form, and in place of eitherstop-screw (but preferably the front stop-screw, as shown in thedrawings) substitute a revolving wheel, A, having a roughened edge.

The operation of my invention is as follows: The Wheel A being made torevolve by clockwork or by any mechanical device, the closing of themain circuit causes the lever B of the receiving-magnet to come intocontact with the wheel A, and thus produce a sound.

Heretofore it has been necessary to give the lever of the receivingmagnet considerable. play when it was necessary to produce a sound, butwith my invention the lever needs but very little play. In fact, it mayrest constantly against the wheel A, and yet, in consequence of thedifferent degrees ot' pressure exerted, produce a sound when the circuitis closed different from the sound produced when the circuit is broken.Y

The wheel A may be either solid or hollow,

